"We are still trying to understand the test results, so that we can investigate and determine what happened,” Geudes said in a statement to MMA Fighting. "What we know as of now is that Junior dos Santos has never taken PEDs, has never knowingly used any banned substances, and has always supported USADA's policies and efforts to keep the sport clean. If ever there was a fighter who made his position on this issue unequivocal, it's Junior. We are confident that that we will be able to figure out what happened, and will provide an explanation once we have one.”

If the failed drug test is proven to be true in the end, it would be the first USADA violation for the former heavyweight champion.

Geudes and the rest of Dos Santos’ team suggest that failed drug test was due to a diuretic and not an illegal substance.

“Junior tested positive for a substance called Hydrochlorothiazite, which is a diuretic and is banned by USADA due to its use as a masking agent,” the statement read. “We do not know where this substance came from. Junior has had his blood and urine randomly tested many times and has never once tested positive for a banned substance. We requested testing of his B sample today. Most times, the B sample will show the identical results as the A sample. Therefore, we are already working on analyzing his nutritional supplements and medications, to determine whether anything might have been contaminated. Jeff Novitzky and Donna Marcolini of the UFC have provided the guidance for this process, and we are grateful to them for their professionalism and competence.”

JDS was set to fight Francis Ngannou at UFC 215, a replacement opponent hasn’t been announced at this time.